1. Field of the Invention
The present invention relates to an ink tank and a tank holder that detachably holds the ink tank, as well as an ink jet head cartridge provided with the tank holder and an ink jet head that performs recording by discharging ink. The invention also relates to an ink jet recording head provided with the ink jet head cartridge.
2. Related Background Art
For the ink jet recording apparatus that records by discharging ink, it is known to arrange the structure so that the recording head that discharges ink and the ink tank that supplies ink to the recording head are formed integrally as an ink jet head cartridge which is separable as one unit from the recording apparatus main body, and at the same time, the ink tank is separable from the recording head on the recording apparatus or the head and the ink tank are made separable from each other in a state of being separated from the recording apparatus. For a structure of the kind, it is required to make the recording head and the ink tank easily separable, but ink is supplied to the head reliably when the ink tank is installed on the recording head.
FIGS. 1A and 1B are views which illustrate one example of an ink jet head cartridge having the recording head and ink tank arranged separably. FIG. 1A is a perspective view which shows the tank holder. FIG. 1B is a cross-sectional view thereof. As shown in FIG. 1B, the upper face of the box type tank holder 103 is open in order to hold the ink tank which will be described later. On one side portion of the lower face of the tank holder 103, the ink jet head 102 is arranged. Also, the upper side face of the tank holder 103 is inclined externally as the guide. Then, upper end portion 43 thereof is formed to abut upon the third pawl 133 of the ink tank which will be described later. For the ink jet head 102, the silicon substrate 201 is supported by the base plate 205. On the silicon substrate 201, heaters that serve as electrothermal transducing members are formed to generate thermal energy which is utilized for discharging ink.
Also, for the ink jet head 102, the joint 204 is formed to be connected with the ink supply port of the ink tank when the ink tank is installed on the tank holder 103. For the joint 204, the ink flow paths 206 are formed toward the silicon substrate 201.
FIGS. 2A to 2C are views which illustrate one example of the ink tank 111 to be installed on the tank holder shown in FIGS. 1A and 1B. FIG. 2A is a perspective view which shows the ink tank 111, observed in the direction toward the second pawl 132. FIG. 2B is a perspective view which shows the ink tank 111 observed in the direction toward the movable lever 130. Also, FIG. 2C is a cross-sectional view which shows the ink tank 111.
As shown in FIGS. 2A and 2B, on one side face of the ink tank 111, the movable lever 130 is arranged with the first pawl 131. On the other side face of the ink tank 111, there are arranged the second pawl 132 that engages with the second hole 242 of the tank holder 103, and the third pawl 133 that abuts upon the upper end 142 of the tank holder 103. The first pawl 131 and the second pawl 132 engage with the first hole 241 and the second hole 242 formed on the tank holder 103 (see FIG. 10), respectively, when the ink tank 111 is installed on the tank holder 103. In this manner, the ink tank 111 is fixed to the tank holder 103. On the lower face of the ink tank 111, the ink supply port 211 is arranged to protrude from that face cylindrically.
Also, as shown in FIG. 2C, in the interior of the ink tank 111, the ink absorbent 136 is housed to retain ink by the absorption of ink which is liquid. In the interior of the ink supply port 221, the joint member 154 is filled to be joined with the ink absorbent 136. When the ink tank 111 is installed on the tank holder 103, ink retained in the ink absolvent 136 is supplied to the ink jet head 102 from the ink supply port 211 through the joint member 154.
FIGS. 3A to 3D are views which illustrate the procedures to install the ink tank on the tank holder 103.
At first, as shown in FIG. 3A, the face of the ink tank 111 on the ink supply port 211 side is directed to the upper surface of the tank holder 103. At the same time, the second pawl 132 of the ink tank 111 is inclined downward. Then, the ink tank is being inserted into the interior of the tank holder 103.
At this juncture, if the ink tank 111 is installed in the diagonal direction as shown in FIG. 3B, the third pawl 133 abuts upon the upper end 143 of the tank holder 103 before the outer circumference of the ink supply port 211 abuts upon the joint member 204 of the head cartridge. Thus, the outer circumference of the ink supply port 211 is prevented from being in contact with the joint member 204. In this manner, the normal setting operation is promoted.
Then, as shown in FIG. 3C, the ink tank is inserted along the inclined face of the tank holder 103 on its side indicated on the right-hand side in FIG. 3C. Here, the second pawl 132 of the ink tank 111 is at first engages with the second hole 242 of the tank holder 103.
Further, as shown in FIG. 3D, the ink tank 111 is pressed into the tank holder 103 so that the movable lever 130 is bent to the inner side to enable the first pawl 131 to engage with the first hold 241 of the tank holder 103. Thus, the ink tank 111 is fixed to the thank holder 103. Also, the third pawl 133 is set in the inner side of the tank holder 103 which is inclined to the outer side.
In this state, ink retained in the ink absorbent 136 is introduced into the ink jet head 202 through the joint member 137 of the ink supply port 211. Then, by the application of energy generated by the electrothermal transducing devices (not shown), ink is discharged from the discharge ports (not shown).
In this respect, when the ink tank 111 is removed, the movable member 130 is bent to the inner side to enable the first pawl 131 to be released from the first hole 241 of the tank holder 103. Then, the ink tank 111 is easily removed from the tank holder 103.
In this way, as shown in FIGS. 1A to 2C, the combination of the ink tank and the recording head provided with the tank holder makes it easier to attach to or detach from each other by the installation method as shown in FIGS. 3A to 3D. Then, ink is reliably supplied to the recording head in the state of the ink tank being installed on the recording head. Now that these requirements are satisfactorily met, this combination is excellent in its practical use.
Nevertheless, as a result of ardent studies of the inventors hereof, it has been found that if the following operations should be carried out, there is a fear that the installation is not made exactly as anticipated, although such installation is not among the operations which are fundamentally expected.
At first, as shown in FIG. 4A, if it is attempted to install the ink tank 111 on the ink holder 103 by holding the ink tank in the horizontal posture and lowering it straightly in such condition. Then, as shown in FIG. 4B, the second pawl 132 is pressed by the side face slightly above the second hole 242 of the tank holder 103, and the first pawl 131 of the movable lever 130 is also caused to stay at the side face slightly above the first hole 241 to make it difficult to press the ink tank 111 any further. As a result, there is a fear that the ink supply port 211 does not join the joint member 204 exactly as anticipated.
Further, even when it becomes difficult to press the ink tank 111 any more as described above, the first pawl 131 of the movable lever 130 still resides in a position slightly above the first hole 241 of the tank holder 103 as shown in FIG. 5. Therefore, if the user presses the ink tank forcefully, the first pawl 131 is allowed to engage with the first hole 241 eventually. As a result, the user may be misled, and commits himself to the wrong recognition as to the installation of the ink tank.
Also, depending on the configuration of a tank holder, the corner portions of the lower face of the ink tank or the leading end of the ink supply port is allowed to slip into the gap in front of the joint when the user intends to install the ink tank by inclining it at a specific angle for the installation on the tank holder. As a result, the installation is not made exactly as anticipated.
Further, as shown in FIG. 1A, if a plurality of ink tanks each having different kind of ink retained in it are arranged to be installed on the tank holder, these erroneous installation also present problems discussed above.
With a view to solving these technical problems, the present invention is designed. It is an object of the invention to provide an ink tank and an ink jet head cartridge capable of installing the ink tank on the ink jet heat safely without any difficulties in a simple and inexpensive method. The invention is also aimed at the provision of an ink jet recording apparatus provided with such ink jet head cartridge.
In order to achieve these objectives, the ink tank of the present invention is to be held detachably on a tank holder provided with a movable lever having a first engaging pawl to engage with a first engagement hole provided for one side wall of the tank holder, and a second engaging pawl to engage with a second engagement hole provided for side wall opposite to the one side wall having the first engagement hole of the tank holder. For this ink tank, the distance S between the outer side face of the base portion of the movable lever of the ink tank and the leading end of the second engaging pawl is set to be larger than the distance between the inner wall faces of the side wall having the first engagement hole of the tank holder and the side wall having the second engagement hole.
Also, an ink jet head cartridge of the present invention comprises an ink tank to retain ink; an ink tank holder to hold the ink tank detachably, having a joint connected with the ink supply port of the ink tank, a first hole to engage with a first pawl of the ink tank, and a second hole to engage with a second pawl of the ink tank on the side face opposite to the side having the first hole; and a recording head unit for discharging ink supplied from the ink supply port. For this ink jet head cartridge, the distance S between the outer side face of the base portion of the movable lever of the ink tank and the leading end of the second engaging pawl is set to be larger than the distance between the inner wall faces of the side wall having the first engagement hole of the tank holder and the side wall having the second engagement hole.
With the structure arranged as described above, it is possible to set the distance S between the outer side face of the base portion of the movable lever of the ink tank and the leading end of the second engaging pawl larger than the distance between the inner wall faces of the side wall having the first engagement hole of the tank holder and the side wall having the second engagement hole. Consequently, unless the normal operation of an installation is carried out, the ink tank is not allowed to enter the tank holder. In other words, if the ink tank is kept in the horizontal posture, and lowered straightly downward as it is for its installation on the tank holder, the second engaging pawl of the ink tank is blocked considerably above the second hole of the tank holder. The first engaging pawl of the movable lever is also blocked on the outer side of the tank holder considerably above the first engagement hole of the tank holder. As a result, it becomes impossible to press in the ink tank any further. In this way, the user can recognize that the ink tank is not installed on the tank holder exactly.
Also, in accordance with another embodiment of the present invention, an ink tank to be held detachably on a tank holder provided with a movable lever having a first engaging pawl to engage with a first engagement hole provided for one side face of the tank holder, and a second engaging pawl to engage with a second engagement hole provided for the other side face of the tank holder opposite to the one side face having the first engagement hole of the tank holder. For this ink tank, the second engaging pawl is configured to be fitted into the second engagement hole only when the ink tank is in a position to be installed on the tank holder.
Also, in accordance with another embodiment of the present invention an ink jet head cartridge comprises an ink tank to retain ink; an ink tank holder to hold the ink tank detachably, having a joint connected with the ink supply port of the ink tank, a first hole to engage with a first pawl of the ink tank, and a second hole to engage with a second pawl of the ink tank on the side face opposite to the side having the first hole; and a recording head unit for discharging ink supplied from the ink supply port. For this ink jet head cartridge, the second engagement hold is configured to be fitted for the second engaging pawl only when the ink tank is in a position to be installed on the tank holder.
With the structure arranged as described above, unless the ink tank is installed on the correct location of the tank holder, the second engaging pawl of the ink tank and the second engagement hole of the tank holder are not allowed to be fitted to each other. Thus, recognizing the wrong installation of the ink tank, the user is prompted to operate the installation again.
In this case, since the third engaging pawl is arranged further above the second engaging pawl, it is possible to know the fitting condition of the ink tank and the ink tank holder before the engagement of the second engaging pawl. Thus, the prevention of the wrong insertion is doubly made by the presence of the third engaging pawl in combination with the second engaging pawl.
In accordance with still another embodiment of the present invention, an ink jet head cartridge comprises an ink tank to retain ink; an ink tank holder to hold the ink tank detachably, having a joint connected with the ink supply port of the ink tank, a first hole to engage with a first pawl of the ink tank, and a second hole to engage with a second pawl of the ink tank on the side face opposite to the side having the first hole; and a recording head unit for discharging ink supplied from the ink supply port. For this ink jet head cartridge, a semicircular rib having a bow-shaped curving face intersecting the inserting direction of the ink tank is arranged on the circumference of the joint of the tank holder for guiding the ink supply port of the ink tank, and a linear rib is arranged to be coupled with the semicircular rib on the side opposite to the joint.
With the structure as described above, it becomes possible to produce an effect that the user can easily install the ink tank on the tank holder with a simple method which is made available at lower costs.
Also, an ink jet recording apparatus of the present invention is provided with a carriage having detachably on it an ink jet head cartridge referred to in the preceding paragraphs, which is supported to be able to reciprocate along the surface of a recording medium, and discharge ink from the recording head unit of the ink jet head cartridge to the recording medium for recording in accordance with electric signals for the ink discharges.
Further, an ink supply system of the present invention comprises a first ink tank to retain first ink; a first ink tank holder to install the first ink tank; a second ink tank to retain second ink; and a second ink tank holder to install the second ink tank. Then, for the first ink tank of this ink supply system, a first pawl extrusion is provided to engage with a first engagement hole of the first ink holder, and a second pawl extrusion is provided to engage with a second engagement hole of the second ink holder, and the first pawl extrusion is the two extrusions arranged in parallel, and given the width of each extrusion as La, the gap between extrusions as Lc, the opening width of the first engagement hole for the first pawl extrusion as Ma, and the gap between openings as Mc, and the second pawl extrusion being one elongated side extrusion and given as Le, and the opening width of the second engagement hole for the second pawl extrusion as Me, the relationship between the first pawl extrusion of the first ink tank and the second engagement hole of the second ink tank holer is to satisfy Lc+2La greater than Me and/or Lc greater than Me and the relationship between the second pawl extrusion of the second ink tank and the first engagement hole of the first ink tank holder is to satisfy Le greater than Ma and/or Le less than Mc.
Further, an ink tank of the present invention used for an ink jet recording apparatus detachably mounting thereon a recording head for discharging first ink, a first holder provided with two first engagement holes arranged in parallel to be able to install a first ink tank retaining first ink in a width Ma and a gap Mc, and a second holder provided with a second engagement hole to be able to install a second ink tank retaining second ink in a width Me, wherein two pawl extrusions are arranged for said ink tank in a width La with a gap Lc to satisfy the relationship of Lc+2La greater than Me and/or Lc greater than Me.
Further, an ink tank of the present invention used for an ink jet recording apparatus detachably mounting thereon a recording head for discharging first ink, a first holder provided with two first engagement holes arranged in parallel to be able to install a first ink tank retaining first ink in a width Ma and a gap Mc, and a second holder provided with a second engagement hole to be able to install a second ink tank retaining second ink in a width Me, wherein one pawl extrusion is arranged for said ink tank in a width Le to satisfy the relationship of Le greater than Ma and/or Le less than Mc.
Other objectives and advantages besides those discussed above will be apparent to those skilled in the art from the description of a preferred embodiment of the invention which follows. In the description, reference is made to accompanying drawings, which form a part hereof. Such example, however, is not exhaustive of the various embodiments of the invention, and therefore reference is made to the claims which follow the description for determining the scope of the invention.